Strain Sensor Could Help Robots Read Facial Expressions

Worn near the lip, the sensor is made of a stacked piezoresisitive nanohybrid film of single-wall carbon nanotubes and a conductive elastomeric composite of polyurethane polystyrenesulfonate. Photo credit: American Chemical Society.)

Developed by researchers in Korea, the stretchable, transparent sensor is worn on a person’s face, near the side of the lip. The sensor, which can detect small strains on human skin, was made by layering a carbon nanotube film on two kinds of electrically conductive elastomers.

Most of the current projects on expression analysis use visual sensors that can tell a smile from a frown, for example. But these systems don’t pick up on subtle eye movements. The new wearable sensor, however, can detect changes in gaze. Experimental results confirm that the sensor could also distinguish whether subjects were laughing or crying.

The researchers also believe the sensor could be useful in health care applications, such as heart rate and breathing monitors.